Device, system, and method utilizing a radiopaque element for anatomical lesion length estimation

ABSTRACT

A catheter is provided with increased flexibility and radiopaque measurement visibility. The radiopaque measurement bands are formed of a continuous coil of radiopaque material defined by areas of tightly packed coils spaced by areas of loosely wound coils. Systems and methods of utilizing the measurement structure are also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.15/660,446, filed Jul. 26, 2017, now U.S. Pat. No. ______, which is acontinuation of U.S. application Ser. No. 13/973,773, filed Aug. 22,2013, now U.S. Pat. No. 9,743,992, which claims priority to and thebenefit of U.S. Provisional Patent Application No. 61/692,603, filedAug. 23, 2012, each of which is hereby incorporated by reference in itsentirety.

BACKGROUND

Catheters have widespread clinical use in both diagnostic andtherapeutic procedures. For example, catheters are used diagnosticallyto inject contrast media, measure internal body dimensions, retrievebiopsy samples, and visually inspect internal body sites. Catheters areused therapeutically to deliver drugs, deliver implants, drain fluids,retrieve foreign and/or undesirable materials, deliver ultrasound,deliver laser light, provide access for minimally invasive surgicalinstruments, and dilate narrowed body passages (e.g., vessels).

In several of these procedures, it is advantageous to be able tovisualize the progress of the catheter towards the target locationwithin a patient's body. Introducing catheters into the body oftenrequires fluoroscopic visualization to aid the treating healthcareprovider in guiding the catheter to the target site. Catheters arecommonly formed of a non-radiopaque polymeric material. Therefore,radiopaque markers may be added to the catheter to enable the catheterto be visualized during x-ray and fluoroscopic procedures. For example,in intravascular catheter procedures, health care providers may guidethe catheter to a target location by using fluoroscopy to track theposition of radiopaque markers on the catheter.

Commonly, these radiopaque markers are circumferential metallic bandsaffixed to the exterior surface of the catheter. Although these markerbands allow the catheter to be visualized by fluoroscopy, they canpresent certain problems. In particular, metallic marker bands requirefixation (e.g., by crimping, swaging, or adhesive) to the underlyingcatheter to avoid slippage as the catheter is moved through the body.The bands may protrude from the tubular surface of the catheter andincrease the catheter profile, which creates frictional resistance tothe translational movement of the catheter through body passages, andpotentially damages tissues contacting the moving catheter. In someinstances, where a marker band has been swaged onto the outer surface ofa catheter and the inner diameter of a marker band is greater than theouter diameter of the catheter, buckling may occur, causing the markerband to crack and the catheter surface to tear. Further, the placementof band markers on the outer catheter surface presents problems withinadvertent disassociation of the markers from the catheter wall, withattendant loss of positional and measurement accuracy. In addition, suchmarker bands are constructed from expensive and heavy radiopaque metalssuch as gold, platinum, tantalum, and alloys of these dense materials.The use of these heavy materials typically results in inflexible andrigid marker bands that can impair the trackability of the catheter byincreasing the stiffness of the catheter, thereby compromising theflexibility and maneuverability of the catheter.

The devices, systems, and methods disclosed herein overcome one or moreof the deficiencies of the prior art.

SUMMARY

In one aspect, the present disclosure provides a device for measuring aninternal structure in a body of a patient. In one aspect the devicecomprises an elongate member and a flexible radiopaque coil wound aboutthe elongate member. In some embodiments, the hollow, flexible elongatemember has a uniform diameter and includes a proximal portion and adistal portion with a central lumen extending therebetween. In someembodiments, the radiopaque coil includes an alternating series oftightly wound sections and loosely wound sections. In some embodiments,the tightly wound sections comprise areas of greater radiopacity thanthe loosely wound sections.

In another aspect, the present disclosure provides an imaging system forcharacterizing and measuring an internal structure in a body of apatient. In some embodiments, the system comprises an elongate memberand an imaging device coupled to the elongate member. In someembodiments, the elongate member is hollow and flexible with a uniformdiameter. In some embodiments, the imaging system includes a radiopaquecoil. In some embodiments, the radiopaque coil is flexible and woundabout the elongate member. In some embodiments, the radiopaque coilincludes a plurality of tightly wound sections separated by looselywound sections.

In another aspect, the present disclosure provides a method ofcharacterizing a structure within a body of a patient. In someembodiments, the method comprises inserting an elongate member includinga radiopaque marker coil positioned at a distal portion of the elongatemember, wherein the radiopaque marker coil has a plurality of evenlyspaced radiopaque tightly wound sections separated by linear intervalsof constant length. In some embodiments, the method further comprisespositioning the radiopaque marker coil of the elongate member adjacent afirst point of interest on the structure and observing a firstradiopaque tightly wound section at the first point of interest of thestructure. The method may further comprise advancing the distal portionof the elongate member through the structure such that first radiopaquetightly wound section is at a second point of interest of the structure;observing a second radiopaque tightly wound section at the first pointof interest of the structure; counting the number of intervalsseparating the first radiopaque tightly wound section and the secondradiopaque tightly wound section; and calculating the linear distancebetween the first point of interest and the second point of interest ofthe structure by converting the number of intervals separating the firstradiopaque tightly wound section and the second radiopaque tightly woundsection into a linear measurement.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory innature and are intended to provide an understanding of the presentdisclosure without limiting the scope of the present disclosure. In thatregard, additional aspects, features, and advantages of the presentdisclosure will be apparent to one skilled in the art from the followingdetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate embodiments of the devices andmethods disclosed herein and together with the description, serve toexplain the principles of the present disclosure. Throughout thisdescription, like elements, in whatever embodiment described, refer tocommon elements wherever referred to and referenced by the samereference number. The characteristics, attributes, functions,interrelations ascribed to a particular element in one location apply tothose elements when referred to by the same reference number in anotherlocation unless specifically stated otherwise.

The figures referenced below are drawn for ease of explanation of thebasic teachings of the present disclosure only; the extensions of thefigures with respect to number, position, relationship, and dimensionsof the parts to form the following embodiments will be explained or willbe within the skill of the art after the following description has beenread and understood. Further, the exact dimensions and dimensionalproportions to conform to specific force, weight, strength, and similarrequirements will likewise be within the skill of the art after thefollowing description has been read and understood.

The following is a brief description of each figure used to describe thepresent invention, and thus, is being presented for illustrativepurposes only and should not be limitative of the scope of the presentinvention.

FIG. 1 is a diagrammatic illustration of an exemplary catheter accordingto one embodiment of the present disclosure.

FIG. 2 is an illustration of a side view of a distal portion of theexemplary catheter shown in FIG. 1, including an exemplary marker coilaccording to one embodiment of the present disclosure.

FIG. 3 is a schematic illustration of the exemplary marker coil shown inFIG. 2.

FIG. 4 is an illustration of a perspective view of a portion of anexemplary marker coil according to one embodiment of the presentdisclosure.

FIGS. 5a-5d illustrate an exemplary method of manufacturing a markercoil on a mandrel according to one embodiment of the present disclosure.

FIG. 6 is an illustration of a cross-sectional view of a distal portionof the exemplary catheter shown in FIG. 1, including a portion of theexemplary marker coil shown in FIGS. 1 and 2.

FIG. 7 is a schematic illustration of an exemplary marker coil within anexemplary catheter according to one embodiment of the presentdisclosure.

FIG. 8 is an exemplary static fluoroscopy image showing an exemplarymarker coil within an exemplary catheter according to one embodiment ofthe present disclosure.

FIG. 9 is a diagrammatic illustration of an exemplary imaging catheteraccording to one embodiment of the present disclosure.

FIG. 10 is an illustration of a cross-sectional view of a distal portionof the exemplary catheter shown in FIG. 9, including exemplary inkedmarkers and a portion of an exemplary marker coil.

FIG. 11 is a diagrammatic illustration of a proximal portion of theexemplary imaging catheter shown in FIG. 9, including exemplary inkedmarkers.

FIG. 12 is a schematic illustration of exemplary inked markers within anexemplary catheter according to one embodiment of the presentdisclosure.

FIG. 13 is a diagrammatic illustration of the exemplary imaging cathetershown in FIG. 9, including exemplary inked markers and a portion of anexemplary marker coil.

FIG. 14 is a schematic illustration of a distal portion of the exemplaryimaging catheter shown in FIG. 9, including a portion of an exemplarymarker coil, an imaging device, and a distal tip.

FIG. 15 is a diagrammatic illustration of a distal portion of theexemplary imaging catheter shown in FIG. 9, including exemplary inkedmarkers.

FIG. 16 is an illustration of the exemplary imaging catheter shown inFIG. 9 positioned within a vessel with the imaging device positioned ata first end of an aneurysm.

FIG. 17 is an illustration of the exemplary imaging catheter shown inFIG. 9 positioned within a vessel with the imaging device advanced to asecond end of an aneurysm.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of thepresent disclosure, reference will now be made to the embodimentsillustrated in the drawings, and specific language will be used todescribe the same. It will nevertheless be understood that no limitationof the scope of the disclosure is intended. Any alterations and furthermodifications to the described devices, instruments, methods, and anyfurther application of the principles of the present disclosure arefully contemplated as would normally occur to one skilled in the art towhich the disclosure relates. In particular, it is fully contemplatedthat the features, components, and/or steps described with respect toone embodiment may be combined with the features, components, and/orsteps described with respect to other embodiments of the presentdisclosure. For the sake of brevity, however, the numerous iterations ofthese combinations will not be described separately. For simplicity, insome instances the same reference numbers are used throughout thedrawings to refer to the same or like parts.

The present disclosure describes devices, systems, and methods to assisthealth care providers with accurate anatomical structure and/or lesioncharacterization using external and/or internal imaging. The accuratemeasurement of anatomical structures and lesions may assist the healthcare provider in diagnosing a condition, deciding on the appropriatecourse of treatment, treating the condition, and evaluating the resultsof the treatment. In one aspect, the present disclosure describesdevices, systems, and methods for providing flexible radiopaque markersassociated with tubular medical devices such as catheters. Inparticular, the present disclosure describes a catheter including aradiopaque marker coil having alternating coiled regions of varyingpitch and, thus, regions of more and less radiopacity. The marker coildisclosed herein provides an apparatus that can be integrated withtubular medical devices and achieve the radiodensity necessary to beable to visualize and characterize anatomical regions of interestwithout compromising the flexibility and maneuverability of the device.The marker coil comprises a single length of material that is coiledinto tightly wound sections having a closed pitch and loosely woundsections having an open pitch. The tightly wound sections form areas ofgreater radiopacity while the loosely wound sections form areas of lessradiopacity. As the catheter curves to travel through a patient's bodilypassages, the marker coil can flex to accommodate for the curvature ofthe catheter without limiting the flexibility of the catheter. In oneaspect, the marker coil is positioned within the catheter wall at adistal portion of the catheter. Moreover, the marker coil disclosedherein may be manufactured more efficiently and at less cost than otherradiopaque markers. In another aspect, the present disclosure describesa catheter including the radiopaque marker coil on a distal portion ofthe catheter as well as inked marker bands on a proximal portion of thecatheter. The combination of radiopaque and proportionally spaced inkedmarkers facilitate the ability of the user to accurately estimateinternal anatomical structure and lesion measurements.

It should be appreciated that while the exemplary embodiment isdescribed in terms of a catheter, the present disclosure is not solimited. Thus, for example, using the marker coil and/or the inkedmarkers disclosed herein on a tubular medical device such as, by way ofnon-limiting example, a guidewire or a probe, is within the spirit andscope of the present disclosure.

Referring to FIG. 1, shown therein is a catheter 100 comprising anelongated, flexible tubular member or body 102 including a central lumen105 that allows the passage of contents from a proximal end 110 througha distal end 115 of the catheter 100. A radiopaque marker coil 120 ispositioned at a distal portion 125 of the body 102. In general, thecatheter 100 is sized and shaped for use within an internal structure ofa patient, including but not limited to a patient's arteries, veins,heart chambers, neurovascular structures, gastrointestinal system,pulmonary system, and/or other areas where internal access of patientanatomy is desirable. In that regard, depending on the particularmedical application, the catheter 100 is configured for use incardiology procedures, neurovascular procedures, pulmonary procedures,endoscopy procedures, colonoscopy procedures, natural orifice procedures(such as Natural Orifice Transluminal Endoscopic Surgery (NOTES)),and/or other medical procedures.

The body 102 is shaped and sized for insertion into bodily passages of ahuman patient. In the pictured embodiment, the body 102 is shaped andconfigured for insertion into a lumen of a blood vessel (not shown) suchthat a longitudinal axis LA of the catheter 100 aligns with alongitudinal axis of the vessel at any given position within the vessellumen. In that regard, the straight configuration illustrated in FIG. 1is for exemplary purposes only and in no way limits the manner in whichthe catheter 100 may curve in other instances. Generally, the elongatebody 102 may be configured to take on any desired arcuate profile whenin the curved configuration. In one instance, the body 102 has anoverall length from the proximal end 110 to the distal end 115 of atleast 90 cm. and in some embodiments, extending to 150 cm. Other lengthsare also contemplated. In some instances, the body 102 has an externaldiameter ranging from 2 F to 9 F (i.e., 0.67 mm to 3 mm).

The body 102 is formed of a flexible material such as, by way ofnon-limiting example, high density polyethylene,polytetrafluoroethylene, Nylon, block copolymers of polyamide andpolyether (e.g., PEBAX), polyolefin, polyether-ester copolymer,polyurethane, polyvinyl chloride, combinations thereof, or any othersuitable material for the manufacture of flexible, elongate catheters.In the pictured embodiment, the body 102 is connected at the proximalend 110 to an adapter 130, which is configured to couple the catheter100 to another medical device at a proximal port 135 and/or through anelectrical connection 137. Various medical devices that may be coupledto the catheter 100 at the proximal port 135 include, by way ofnon-limiting example, a storage vessel, a disposal vessel, a vacuumsystem, a syringe, an infusion pump, and/or an insufflation device.Various devices that may be coupled to the catheter 100 by theelectrical connection 137 include, by way of non-limiting example, anenergy generator (e.g., an ultrasound generator), a power source, apatient interface module (“PIM”), a computer system, and/or a surgicalconsole.

The lumen 105 is shaped and configured to allow the passage of fluid,cellular material, or another medical device (e.g., a guidewire) fromthe proximal end 110 to the distal end 115. In some embodiments, thelumen 105 is sized to accommodate the passage of a guidewire. In such anembodiment, the lumen 105 has an internal diameter greater than 0.014inches.

The distal end 115 is configured to be inserted into a body cavity,tissue, or tubular organ system of a patient. In some embodiments, thecatheter 100 includes a distal tip 140 terminating in the distal end115. In some embodiments, the distal tip 140 is tapered to facilitateinsertion of the body 102 into a patient. In other embodiments, thedistal tip 140 may be blunt, angled, or rounded.

The marker coil 120 is coiled or wound about the distal portion 125 ofthe body 102, and has a length L extending from a first end 145 to asecond end 150. In various embodiments, the marker coil 120 may have alength L ranging from 1 cm to 150 cm. In the pictured embodiment, forexample, the marker coil 120 has a length L of 24 cm. The marker coil120 comprises a single length of material that is coiled into tightlywound sections 155 having a closed pitch and loosely wound sections 160having an open pitch and greater inter-coil spacing than the tightlywound sections. In the pictured embodiment, the marker coil 120 includes25 tightly wound sections 155. In other embodiments, the marker coil mayhave any number of tightly wound sections. The tightly wound sections155 form areas of greater radiopacity while the loosely wound sections160 form areas of less radiopacity. Thus, the tightly wound sections 155effectively form radiopaque markers separated from each other by theloosely wound sections 160. In one embodiment, the radiopaque materialhas an external diameter ranging from 0.022 in. to 0.080 inches (i.e.,0.56 mm to 2.03 mm). In some embodiments, the radiopaque material has anexternal diameter approximating the external diameter of the catheterbody.

As shown in FIG. 2, illustrating a section of the distal portion 125 ofthe body 102, the marker coil 120 comprises the tightly wound sections155 separated by the loosely wound sections 160. As mentioned above, themarker coil 120 is formed of a single length of radiopaque material thathas been wound into areas of varying pitch. The radiopaque material maybe one or more radiopaque metals including, but not limited to, gold,tungsten, iridium, rhodium, platinum, barium, bismuth, and combinationsand/or alloys thereof. However, any material with a high enoughradiodensity when shaped into a tightly wound section 155 is suitablefor the marker coil 120. For example, the marker coil 120 may be formedof lower cost alternatives to precious metals with equivalentradiodensity. In some embodiments, the radiopaque material is aradiopaque polymer, which may comprise a matrix of a polymeric materialin combination with a radiopaque metal, such as are described above.

As shown in FIGS. 2 and 3, the tightly wound sections 155 are tightlywound areas of the marker coil 120 that form blocks of greaterradiopacity or radiodensity than the loosely wound sections 160. In someembodiments, the tightly wound sections 155 have a width W ranging from1.0 mm to 2.0 mm. In the pictured embodiment in FIG. 3, the tightlywound sections 155 have a width W of approximately 1.5 mm. Both thetightly wound sections 155 and the loosely wound sections 160 retain theability to flex, albeit to different degrees. Given the increasedflexibility of the radiopaque tightly wound sections 155, the tightlywound sections 155 may have greater widths W (and greater resultantvisibility) than rigid, metallic marker bands. Thus, the tightly woundsections 155 form flexible radiopaque markers with spring-likefunctionality that are capable of curving with the catheter 100 as ittraverses through tortuous anatomy without causing the inadvertentcatheter kinking and/or trauma that can be caused by rigid marker bands.

The tightly wound sections 155 have a closed pitch while the looselywound sections have an open pitch. In other words, as shown in FIG. 3,the tightly wound sections 155 are formed of tightly compressedindividual coils 162 of the marker coil 120 having little to no spacebetween them, while the loosely wound sections 160 are formed by coils162 having greater space between centers of adjacent coils 162. In someembodiments, the pitch of the coils 162 in the loosely wound sections160 may range from 1.1938 mm (0.047 inches) to 1.3462 mm (0.053 inches).In the pictured embodiment, the loosely wound sections 160 are formed byfour loosely wound turns or coils 162 of the marker coil 120. However,the loosely wound sections 160 may be formed by any number of coils 162.

In one embodiment, the marker coil 120 is manufactured by stretching atightly compressed coil at constant intervals past the recovery point ofthe coil material, thereby creating alternating areas of tightly woundcoil and loosely wound coil. Stretching the coil past its recovery point“sets” the intervals between the individual coils (e.g., coils 162) andcreates constant intervals between the tightly wound sections 155 andthe loosely wound sections 160. For example, in the pictured embodimentin FIG. 3, the tightly wound sections 155 are separated from one anotherby a constant interval I1, which reflects a fixed distance betweenadjacent tightly wound sections 155. Similarly, the loosely woundsections 160 are separated from one another by a constant interval I2,which reflects a fixed distance between adjacent loosely wound sections160. The interval I1 may vary in different embodiments depending uponthe particular application desired. For example, in various embodiments,the interval I1 may range from 0.5 cm to 5 cm. In some embodiments, theinterval I1 of the marker coil is 1 cm. Stretching the coil past itsrecovery point to create constant intervals between the tightly woundsections 155 and the loosely wound sections 160, as well as between theindividual coils 162, strengthens the marker coil 120.

As shown in FIG. 4, in one embodiment, the marker coil 120 may bemanufactured on a mandrel 164. As shown in FIG. 5a , the marker coil 120may be fixed (e.g., with a fixation device) in an un-stretched conditionat the first end 145 about the cylindrical mandrel 164 before beingstretched at constant intervals past the recovery point of the coilmaterial, thereby creating alternating areas of tightly wound sections155 and loosely wound sections 160. In particular, as shown in FIG. 5b ,a tightly wound section 155 a of the marker coil 120 may be releasablyanchored to the mandrel 164 at a coil 165 before the marker coil isstretched in a direction opposite the first end 145 to create a looselywound section 160 a of a desired length L2. The distance between a coil166 and the coil 165 may be selected based upon a desired width W1 ofthe tightly coiled section 155 a. As shown in FIG. 5c , the marker coil120 may be releasably anchored to the mandrel 164 at a coil 167 of atightly wound section 155 b before the marker coil is stretched in adirection opposite the first end 145 to create a loosely wound section160 b of a desired length L3. The distance between a coil 168 and thecoil 167 may be selected based upon a desired width W2 of the tightlywound section 155 a. In some embodiments, the widths W1, W2 may besubstantially the same, but in other embodiments, the widths ofindividual tightly wound sections may vary in accordance with thedesired application for the radiopaque markers. Similarly, in someembodiments, the lengths L2, L3 may be substantially the same, but inother embodiments, the lengths of individual loosely wound sections mayvary in accordance with the desired application. As illustrated by FIG.5d , this process may be repeated until the marker coil 120 comprisesthe desired number and arrangement of alternating tightly wound sections155 and loosely wound sections 160. Thus, the marker coil 120 has highlyradiopaque tightly wound sections 155 alternating with less radiopaqueloosely wound sections 160 at substantially constant intervals, allowingthe catheter 100 to serve as an internal marking or measuring device.

In the embodiment shown in FIG. 6, the marker coil 120 is at leastpartially enclosed within an outer wall 170 of the catheter body 102.The outer wall 170 extends from an inner surface 172 to an outer surface174. In the pictured embodiment, the inner surface 172 forms a luminalsurface of the catheter 100 adjacent the lumen 105. In at least oneembodiment, the marker coil 120 is completely enclosed between the innersurface 172 and the outer surface 174. In some embodiments, an edge orend of the marker coil may by exposed through the outer surface 174and/or the inner surface 172 of the outer wall 170. For example, in someembodiments it may be desirable for an edge or end of the marker coil120 to protrude from the wall 170 to anchor itself or other cathetercomponents (e.g., a balloon or a stent) to the body 102.

The marker coil 120 can be placed within and/or about the outer wall 170in accordance with a variety of methods. In the pictured embodiment, theouter wall 170 includes a lumen 176 sized and configured to receive themarker coil 120 during manufacture of the catheter 100 withoutincreasing the outer diameter D or profile of the body 102 of thecatheter 100. The lumen 176 comprises an annular space extending betweenthe inner surface 172 and the outer surface 174. The space within thelumen 176 allows the radiopaque marker coil 120 to bend and flex freelybeneath the outer wall 170. In some embodiments, the marker coil 120 maybe wound directly onto the catheter (i.e., into the inner surface 172)under tension before the incorporation of the outer surface 174 to forma series of flexible radiopaque markers that are embedded within theouter wall 170. For example, the outer surface 174 of the outer wall 170may be applied as a polymeric solution over the marker coil 120, or as aheat-shrink film that is wrapped around the coil 120.

In some instances, such as where the radiopaque material of the markercoil 120 is a metal wire, the material of the outer wall 170 is softerthan the radiopaque material of the marker coil. In such instances, themarker coil 120 may be directly embedded into the outer wall 170 bysliding the marker coil over the distal portion 125 of the body 102 anddirectly apply force to the marker coil to push it into the material ofthe outer wall. For example, in some embodiments, a compressiveapparatus (e.g., a roller assembly) may be used to physically press themarker coil 120 circumferentially and along its length into the outerwall 170 of the catheter 100. In some instances, the outer surface 174may include indentations, grooves, or other surface features shaped andconfigured to receive the marker coil 120 without disrupting the innersurface 172 or increasing the outer diameter D or profile of the body102 of the catheter 100. In some embodiments, the marker coil 120 isincorporated into the outer wall 170 of the catheter 100 in such amanner as to maintain a smooth outer surface of the catheter 100. Such asmooth surface has improved lubricity over a comparable catheter havingmetallic marker bands disposed around the outer wall 170.

FIG. 7 is a schematic illustration of the marker coil 120 enclosedwithin an outer wall 170 of the body 102 of the catheter 100. In someembodiments, the marker coil 120 acts as a support mechanism to the wall170 of the catheter 100 and lends an additional degree of stiffness tothe distal portion 125 of the body 102 of the catheter 100. As a result,the distal portion 125 may be provided with greater longitudinalstiffness, which may improve the device pushability of the catheter 100.

The method of stretching a single coil to form the more radiopaque,tightly wound sections 155 separated by constant intervals I1 creates abound series of radiopaque markers, and the method of integrating theunitary marker coil 120 with the catheter 100 avoids the need toindividually place radiopaque markers along a medical device. Theembodiments disclosed herein eliminate the need to individually place orswage separate radiopaque markers onto a medical device. Instead, theunitary marker coil 120 comprises several constantly spaced tightlywound sections 155 or radiopaque markers that may be integrated into thebody 102 of the catheter 100 without disturbing their predetermineddistances from one another. Therefore, the embodiments disclosed hereinavoid the positioning errors associated with the discrete placement ofindividual radiopaque markers (e.g., marker bands). Moreover, theembodiments disclosed herein allow for a less expensive and possiblyless time-consuming manufacturing process than that required by thediscrete placement of individual radiopaque markers.

FIG. 8 illustrates a fluoroscopic or X-ray image 400 showing thecatheter 100 positioned within a patient. In particular, the distalportion 125 of the catheter 100 is shown extending through the coronaryvasculature. The tightly wound sections 155 of the marker coil 120 areprominently visible on the image 400, while the less radiopaque looselywound sections 160 are less prominently highlighted on the image 400. Ahealthcare provider may utilize the marker coil 120 to evaluate,localize, and measure anatomical structures and lesions as describedbelow in relation to FIGS. 16 and 17. In addition, the healthcareprovider may draw conclusions about the three-dimensional structure orplane of curvature of the intraluminal structure and/or lesion byobserving the relative distances between adjacent tightly wound sections155. For example, shortened or absent intervals I1 between adjacenttightly wound sections 155 on the image 400 may indicate an out-of-planedeflection of the catheter 100. In other words, shortened or absentintervals I1 between adjacent tightly wound sections 155 on the image400 may indicate curvature of the catheter 100 in a third dimension or az-plane. Such data could be used in combination with angiography and/orintravascular imaging to generate a three-dimensional representation ofthe marker coil 120 and/or the intraluminal structure and/or lesionwhere the marker coil is located.

Referring back to FIG. 1, in some embodiments, the catheter 100 includesan imaging device, such as, by way of non-limiting example, anintravascular ultrasound (“IVUS”) transducer 200. Thus, in someembodiments, the catheter 100 may comprise an IVUS catheter. In suchembodiments, the catheter 100 may be connected at the electricalconnection 137 to an IVUS imaging system. In the pictured embodiment,the distal tip 140 houses the transducer 200. The marker coil 120provides radiopaque markers in the form of the tightly wound sections155 to assist in positioning the transducer 200 within a patient'svasculature and obtaining accurate visualization and measurements of thepatient's vessels. In some instances, the imaging device may be used todetermine the morphology and pathology of a target lesion within apatient's anatomy (e.g., a restriction within a vessel). The radiopaquetightly wound sections 155 allow for the accurate localization andmeasurement of such a lesion. Intraluminal imaging may be done as aninitial step to help determine the best applicable therapy, to observe atherapeutic measure in real-time, or as a later step to assess theresults of a given therapy.

It should be appreciated that while the exemplary embodiment isdescribed in terms of an ultrasonic device, to render images of avascular object, the present disclosure is not so limited. It should benoted that the catheter 100 depicted herein is not limited to aparticular type of device, and includes any of a variety of imagingdevices. Thus, for example, using backscattered data (or atransformation thereof) based on other sources of energy, such aselectromagnetic radiation (e.g., light waves in non-visible ranges suchas used in Optical Coherence Tomography, X-Ray CT, spectroscopy, etc.),to render images of any tissue type or composition (not limited tovasculature, but including other structures within a human or non-humanpatient) is within the spirit and scope of the present disclosure.

With reference to FIG. 1, in some embodiments, the catheter 100 includesan expandable device 300, such as, by way of non-limiting example, aballoon apparatus and/or a stent. The expandable device 300 may bepositioned about the distal tip 140 and/or the distal portion 125. Theexpandable device 300 may be positioned around the coil marker 120 suchthat the radiopaque portions of the coil marker 120 can be visualized onfluoroscopy through the expandable device as the catheter 100 ismaneuvered through the patient's body. The marker coil 120 providesradiopaque markers in the form of the tightly wound sections 155 toassist in positioning the expandable device 300 within a patient'svasculature and obtaining accurate visualization and measurements of thepatient's vessels. In some embodiments, the length of the expandabledevice 300 is at least as long as the length L of the coil marker 120extending from the first end 145 to the second end 150.

In some instances, the catheter 100 is used to deliver a medical devicesuch as a balloon, a stent, a graft, a stent-graft, a vena-cava filter,or other implantable medical device, hereinafter collectively referredto as the expandable device 300. For example, the expandable device 300may comprise a self-expanding stent or may comprise a balloon used todeliver and/or deploy a balloon-expandable stent. In some instances, theexpandable device 300 comprises a drug-eluting device such as adrug-eluting balloon or a drug-eluting stent. The radiopaque markersprovided by the tightly wound sections 155 may assist in the preciseintravascular delivery and deployment of the expandable device 300. Inparticular, the expansion of the expandable device 300 may be monitoredusing fluoroscopy-mediated visualization of the radiopaque tightly woundsections 155. In some instances, the expandable device 300 is positionedabout the wall 170 of the catheter 100 in such a manner as to ensurethat the expandable device 300 does not extend substantially beyond thelength L of the marker coil 120.

Due to the non-linear nature of many body lumens, it is often desirableto measure the length of a body lumen along a center line extendingaxially through the center of the body lumen. Such measurements can beuseful in selecting an appropriately sized luminal implant orprosthesis. In that regard, in some instances, the expandable device 300comprises a positioning element shaped and configured to center thecatheter 100 within a lumen (e.g., a curved lumen) so as to facilitatethe accurate measurement of an intraluminal structure or lesion. Such anexpandable device may have a diameter in an expanded state that at leastcorresponds to the diameter of the body lumen. In this way, theexpandable device 300 can be expanded to center the catheter 100 withinthe body lumen, thereby allowing the length of the lesion (or area ofinterest within the lumen) to be measured along the center of the bodylumen.

FIG. 9 shows an imaging catheter 500 including the marker coil 120 and aplurality of inked markers 505 according to one embodiment of thepresent disclosure. The imaging catheter 500 is substantially similar tothe catheter 100 except for the differences noted herein. The catheter500 comprises an elongate, tubular member or body 510 extending from aproximal end 515 to a distal tip 525 that terminates at a distal end520, an imaging device 530 disposed on an imaging housing 532, and anadapter 130 coupling the body 510 to a PIM 535.

The body 510 is substantially similar to the body 102 of the catheter100 except for the differences noted herein. The body 510 includes aproximal shaft portion 540, which includes the plurality of inkedmarkers 505, and a distal shaft portion 545, which includes the markercoil 120. As shown in FIG. 10, the body 510 comprises an inner tubularmember 550 disposed within an outer tubular member 555. The innertubular member 550 extends the length of the body 510 and is coupled ateither end to the adaptor 130 and the distal tip 525 (shown in FIG. 9).In some embodiments, the inner tubular member 550 is heat bonded to theadapter 130 and the distal tip 525. However, any of a variety ofcoupling methods may be employed to secure the inner tubular member 550to the adaptor 130 and the distal tip 525.

In the pictured embodiment, the inner tubular member 550 comprises adarkly colored, elongate, cylindrical tube. The inner tubular member 550defines a lumen 560 extending the length of the body 510 from theadaptor 130 to the distal tip 525. The lumen 560 is substantiallyidentical to the lumen 105 described above in relation to FIG. 1.

The outer tubular member 555 comprises a clear cylindrical sleeve thatextends from the adapter 130 to the imaging device housing 532. In someembodiments, the outer tubular member 555 is secured to the adapter 130and the imaging device housing 532 by means of an adhesive. However, anyof a variety of coupling methods may be employed to secure the outertubular member 555 to the adaptor 130 and the imaging device housing532. The outer tubular member 555 includes a smooth outer surface 556configured to reduce the amount of friction created on an introducerdevice during insertion and removal of the catheter 500, therebyfacilitating smooth and accurate pullbacks during imaging procedures.

As shown in FIG. 10, the plurality of inked markers 505 are disposed onthe inner tubular member 550. The inked markers 505 comprise directvisualization markers that may be viewed during use with the naked eye(or with the use of an endoscope), in contrast to the tightly woundsections 155 of the marker coil 120, which comprise radiopaque markers.The inked markers 505 comprise lightly-colored markings on an exteriorsurface 562 of the inner tubular member 550. The lightly-colored inkedmarkers 505 appear clearly against a background of the darkly-coloredinner tubular member 550 and can be visualized easily through the clearouter tubular member 555 with and without the use of light. In alternateembodiments, the inner tubular member may be light-colored while theinked markers are darkly-colored, provided there is adequate contrastbetween the colors of the inner tubular member and the inked markers topermit visualization through the outer tubular member 555. For example,in some embodiments, the inner tubular member 550 may have a dark color,such as black, dark blue, dark grey, or the like, while the inkedmarkers 505 have a light color such as white, light blue, light green,pink, or the like. The high contrast between the plurality of inkedmarkers 505 and the inner tubular member 550 facilitates visualizationof the markers in a low light environment, such as a darkened operatingroom.

The inked markers 505 may be formed of a variety of suitable inks, whichare typically indelible. Because the inked markers 505 are shielded fromthe patient's anatomy by the outer tubular member 555, the ink does notnecessarily have to be biocompatible. In some embodiments, the inkedmarkers 505 may be formed of a fluorescent substance, thereby enablingthe inked markers to be more clearly visualized in a low lightenvironment, such as a darkened operating room. The inked markers 505can be applied to the inner tubular member 550 by any of a variety ofsuitable methods, including, without limitation, painting, spraying,masked dipping (i.e., dipping the body 510 in ink with parts of the bodymasked to avoid being coated by the ink), and electrostatic attraction.

FIG. 11 illustrates a portion of the proximal shaft portion 540, whichincludes the plurality of inked markers 505. In the pictured embodiment,the plurality of inked markers 505 comprise markers of different widths.In particular, the plurality of inked markers 505 comprise inked markers563, which have a width W3, and inked markers 564, which have a widthW4. In various embodiments, the widths of the individual inked markersmay be uniform or different, depending upon the desired application ofthe inked markers 505 and/or the catheter 500. The widths of theindividual inked markers may range from 0.5 mm to 5.5 mm. In at leastone embodiment, the width W3 is approximately 1.0 mm and the width W4 isapproximately 5.0 mm.

FIG. 12 illustrates the proximal shaft portion 540 of the catheter 500,including the inked markers 563, 564. In other embodiments, any numberof inked markers 563 and the inked markers 564 may be positioned on theinner tubular member 550 in any of a variety of combinations orarrangements. In some embodiments, the inked markers 563 and 564 mayhave the same width, comprising a plurality of equally-sized inkedmarkers. In some embodiments, the inked markers 563 may have a differentcolor than the inked markers 564 to facilitate distinguishing themarkers 563, 564 from one another during use. In the pictured embodimentin FIG. 13, the inked markers 563 and the inked markers 564 are arrangedin a repeating pattern of four inked markers 563 and one inked marker564. The inked markers 563 and the inked markers 564 are separated fromone another by an interval 13. The interval 13 may vary in differentembodiments depending upon the particular application desired. Theinterval 13 may range from 3.0 mm to 20.0 mm. For example, in thepictured embodiment in FIG. 11, the interval 13 measures approximately 1cm, which reflects a fixed distance between adjacent inked markers 505.

Returning to FIG. 10, the outer tubular member 555 circumferentially andlongitudinally surrounds the inner tubular member 550, creating anannular space or lumen 565 therebetween. In the pictured embodiment, themarker coil 120 is at least partially enclosed in the lumen 565 betweenthe inner tubular member 550 and the outer tubular member 555 at thedistal shaft portion 545. In at least one embodiment, the marker coil120, including the tightly wound sections 155 and the loosely woundsections 160, is completely enclosed in the lumen 565 at the distalshaft portion 565. In the pictured embodiment of FIG. 9, the marker coil120 comprises twenty-five tightly wound sections 155 separated from eachother by approximately 100 mm.

FIGS. 14 and 15 show the distal shaft portion 545 of the catheter 500,including the imaging device 530 positioned proximal to the distal tip525 at the imaging device housing 532. The distal tip 525 is configuredto be inserted into a body cavity, tissue, or tubular organ system of apatient. In the illustrated embodiment, the distal tip 525 is tapered tofacilitate insertion of the body 510 into a patient. As shown in FIG.15, the distal tip 525 has a length L4 ranging from 10 mm to 20 mm. Invarious embodiments, the length L4 varies depending upon the particularapplication of the catheter 500. For example, in the picturedembodiment, the length L4 is approximately 12 mm.

The image device housing 532 has a length L5 ranging from 1.5 mm to 10.0mm. In various embodiments, a length L5 varies depending upon theparticular type of imaging device 530 and the particular application ofthe catheter 500. In the pictured embodiment, the imaging device 530comprises an ultrasound transducer (e.g., by way of non-limitingexample, a solid state phased array, a rotational, FLIVUS, and/or PMUTtransducer). However, in other embodiments, the imaging device 530 maycomprise any of a variety of imaging devices, including, by way ofnon-limiting example, an OCT or laser-emitting device. For example, inthe pictured embodiment where the imaging device 530 comprises anultrasound transducer, the length L5 is approximately 6.5 mm.

In the pictured embodiment in FIG. 15, the tightly wound sections 155 ofthe marker coil 120 are separated from each other and the imaging device530 by an interval I1, as described above in relation to FIG. 3. Theinterval I1 may vary in different embodiments depending upon theparticular application desired. For example, in the pictured embodiment,the interval I1 of the marker coil 120 is 1 cm.

FIGS. 16 and 17 illustrate an exemplary instance where the catheter 500,with its combination of proximally-positioned inked markers 505 and itsdistally-positioned marker coil 120, can be used to assist thehealthcare professional with accurate and efficient lesion measurementand evaluation. In FIG. 16, the distal shaft portion 545 of the catheter500 is positioned within a vessel 600, which includes a intravascularlesion 605. In the pictured embodiment, the vessel 600 comprises anaorta and the intravascular lesion comprises an aortic aneurysm, whichis an abnormal dilation of the aorta. However, the catheter 500 (or thecatheter 100 described above) may be used to evaluate a variety oflesions and/or structures, as described further below.

In FIG. 16, the distal shaft portion 545 of the catheter 500 is shownpositioned within the vessel 600 such that the marker coil 120 islocated adjacent to the lesion 605. In particular, the distal-mosttightly wound section 155 c is positioned immediately proximal thelesion 605, which may be visualized with contrast during fluoroscopy,without contrast during fluoroscopy (i.e., by visualizing the radiopaquetightly wound sections 155), and/or with the use of the imaging device530. During fluoroscopy, the tightly wound sections 155 of the markercoil 120 remain visible, thereby allowing the healthcare provider toposition the marker coil 120 relative to margins of the lesion 605 tomeasure various dimensions of the lesion 605. In some instances, thehealthcare professional may visualize the lesion 605 using fluoroscopyto accurately position the radiopaque tightly wound section 155 c at afirst end 606 of the lesion 605. In some instances, the healthcareprofessional may use the imaging device 530 to localize the lesion 605and accurately position the radiopaque tightly wound section 155 c atthe first end 606 of the lesion 605. For example, the imaging device 530may be used to localize relevant anatomical landmarks and/or the marginsof the lesion 605. In some instances, the healthcare professional mayuse a combination of extravascular imaging (i.e., fluoroscopy) andintravascular imaging (i.e., with the imaging device 530) to localizethe lesion 605 and accurately position the radiopaque tightly woundsection 155 c at the first end 606 of the lesion 605.

Intravascular imaging can occur before or after interventionaltreatment. When used before such treatments, the images may aid thehealthcare profession in localizing the lesion 605 and in decidingwhether and/or how to treat the lesion. For example, in the case ofaneurysms, the imaging device 540 may be used to evaluate the health ofthe tissue wall prior to selecting an implanting a stent graft to repairthe aneurysm and selecting anchor points for the stent/graft. Moreover,the imaging device 540 may be used to determine both the position andorientation of the tightly wound sections 515 (i.e., as the distal shaftportion 545 is curved to approximate the boundaries of the lesion 605)to assist in evaluating the lesion 605. For example, the imaging device540 may be utilized to determine position of individual tightly woundsections 515 relative to each other to evaluate the shape and/orcurvature of the lesion 605. The resulting data may be utilized toconstruct a three dimensionally significant representation of the lesion605 as indicated by the positions of the tightly wound sections 515.Such a representation could yield a length, diameter, and/or radius ofcurvature of a lesion 605, all of which could be used to assist in theselection of an appropriately sized prosthetic or implant, such as astent graft for repairing an aneurysm.

When used after a given treatment, the images may aid the healthcareprofessional in the assessment and documentation of the results of thetreatment. Utilizing intravascular imaging from the imaging device 540in combination with the radiopaque tightly wound sections 155 of themarker coil 120 enables the healthcare provider to use less contrastduring the localization and the measurement of the lesion 605. Moreover,the positions of the radiopaque tightly wound sections 155 observed withfluoroscopy may be co-registered with the positions of the tightly woundsections 155 observed with intravascular imaging to enhance theevaluation, localization, and measurement of the lesion 605.

Once the distal-most tightly wound section 155 c is positioned at thefirst end of the lesion 605, the healthcare provide can note therelevant inked markers 505 as described below and perform whateverdiagnostic and/or therapeutic measures may be indicated for theparticular procedure he or she is performing. Thereafter, the healthcareprovider can advance the catheter 500 into the vessel 600 until thetightly wound section 155 c is positioned at a second end 607 of thelesion 605.

In FIG. 17, the distal-most tightly wound section 155 c is positioned ata second end 607 of the lesion 605, which may be visualized withcontrast during fluoroscopy, without contrast during fluoroscopy (i.e.,by visualizing the radiopaque tightly wound sections 155), and/or withthe use of the imaging device 530 as described above. The healthcareprovider can use the marker coil 120 to estimate the length and/or otherdimensions of the lesion 605. In some instances, the healthcare providercan observe which particular tightly wound section 155 d is positionedat the first end 606 of the lesion 605 when the distal-most tightlywound section 155 c is positioned at the second end 607 of the lesion605. By comparing the tightly wound section 155 c to the tightly woundsection 155 d, the healthcare provider may estimate the length of thelesion 605. In particular, by counting the number of intervals I1between the tightly wound section 155 c and the tightly wound section155 d, and correlating that number of intervals to a length measurement,the healthcare provider can estimate the length of the lesion 605. Asdescribed above, the spacing between the tightly wound sections 155 canbe of a constant length interval I1 so that the healthcare professionalcan convert the difference in the number of intervals into acorresponding length measurement. For example, in the example shown inFIGS. 16 and 17, there are nine intervals I1 between the tightly woundsection 155 c and the tightly wound section 155 d. Given that eachinterval I1 of the marker coil 120 measures 100 mm or 1 cm, the lengthof the lesion 605 is approximately 900 mm or 9 cm. Thus, the multipletightly wound sections 155 of the marker coil 120 provide severalradiopaque markers that allow for more accurate measurement of variousdimensions of an anatomical structure and/or lesion than a measuringdevice having only a few radiopaque markers.

The plurality of inked markers 505 allow the healthcare professional tovisually detect how far the catheter 500 is axially moved with respectto a reference point such as a proximal end 610 of an introducer 615. Atleast some of the proximal shaft portion 540 of the catheter 500 ispositioned outside the patient's body, allowing the healthcareprofessional to estimate the length of the catheter 500 that has beeninserted into the patient's body by observing the number of inkedmarkers 505 still visible outside the patient's body. In addition, thehealthcare professional may estimate the length of the intravascularlesion 605 by noting a first number of externally visible inked markers505 when the catheter 500 is positioned at the first end 606 of thelesion 605 as shown in FIG. 16, noting a second number of externallyvisible inked markers 505 when the catheter 500 is positioned at thesecond end 607 of the lesion 605 as shown in FIG. 17, and comparing thetwo values. In particular, the difference between the first number andthe second number can be used to estimate the length of the lesion 605.As described above, the spacing between the inked markers 505 can be ofa constant length interval so that the healthcare professional canconvert the difference in the number of inked markers into a lengthmeasurement corresponding to how far the catheter 500 has axially movedwith respect to a reference point such as a proximal end 610 of anintroducer 615.

In another instance, the healthcare professional can observe aparticular inked marker 505 a present at a reference point outside thepatient's body, such as the proximal end 610 of the introducer 615, whenthe catheter 500 is positioned at the first end 606 of the lesion 605 asshown in FIG. 16, observe a particular inked marker 505 b present at thesame reference point when the catheter 500 is positioned at the secondend 607 of the lesion 605 as shown in FIG. 17, and comparing the lengthmeasurements indicated by the inked markers 505 a, 505 b. Each inkedmarker 505 is positioned a particular distance from the proximal end 515of the catheter 500. For example, if the inked marker 505 a ispositioned 30 cm from the proximal end 515 and the inked marker 505 b ispositioned 22 cm from the proximal end 515, the healthcare professionalmay estimate that the length of the lesion 605 is 8 cm.

Once the lesion 605 has been measured, the healthcare provide canperform whatever diagnostic and/or therapeutic measures may be indicatedfor the particular procedure he or she is performing. For example, insome embodiments, the healthcare professional may advance the catheter500 into the lesion 605 and image the lesion 605 using the imagingdevice 530. In other instances, the healthcare professional may expandan expandable device similar to the expandable device 300 shown inFIG. 1. Knowing the accurate length and/or other dimensions of thelesion 605 will help the healthcare provider to determine theappropriate course of treatment, appropriately evaluate the results of agiven treatment, and/or appropriately position any implantable devicesfor treating the lesion 605. For example, in the situation illustratedby FIGS. 16 and 17, the healthcare provider may select an appropriatelysized stent and expand the stent within the lesion 605 (i.e., ananeurysm) within the vessel 600.

Embodiments in accordance with the present disclosure provide users withan accurate and efficient device, system, and method for evaluating,localizing, and measuring anatomical structures and/or lesions to planan appropriate treatment course and/or evaluate a given treatment.Proximal inked markers and/or a distal radiopaque marker coil inaccordance with the present disclosure may be used alone or incombination in a variety of applications to evaluate, localize, andmeasure anatomical structures and/or lesions. For example, but not byway of limitation, embodiments of the present disclosure may be used toassist in evaluating an intraluminal site for implantation of aprosthesis (e.g., a drug-eluting balloon, a drug-eluting stent, a stentgraft, a bioresorbable stent), PTCA balloon location, an endovascularaneurysm repair (e.g., of the abdominal or thoracic aorta), IVC filterplacement (e.g., in the inferior vena cava), evaluation of tumorgrowth/response to treatment, and a variety of other procedurespreviously utilizing a separate measuring device (e.g., a ruler) forlesion measurement. In addition, embodiments of the present disclosuremay be used to monitor the position and/or efficacy of already implanteddevices such as, but not by way of limitation, stents, stent grafts,drug-eluting stents, drug-eluting balloons, and orthopedic implants(e.g., bone screws or hip, shoulder, or knee implants). Moreover, themarkers of the present disclosure enable the elimination of at least onepigtail marker catheter exchange in several procedures, such as a lowcontrast endovascular aneurysm repair procedure, thereby acceleratingthe process of stent-graft length sizing assessment. Some embodiments ofthe present disclosure may be used in a variety of organ systems suchas, but not by way of limitation, the circulatory system, the lymphaticsystem, the digestive system, the pulmonary system, the orthopedicsystem, and the neurological system.

Persons of ordinary skill in the art will appreciate that theembodiments encompassed by the present disclosure are not limited to theparticular exemplary embodiments described above. In that regard,although illustrative embodiments have been shown and described, a widerange of modification, change, and substitution is contemplated in theforegoing disclosure. It is understood that such variations may be madeto the foregoing without departing from the scope of the presentdisclosure. Accordingly, it is appropriate that the appended claims beconstrued broadly and in a manner consistent with the presentdisclosure.

What is claimed is:
 1. An intravascular device comprising: a catheterconfigured to be positioned within a blood vessel of a patient, thecatheter defining a lumen; and a radiopaque wire comprising a singlepiece of material arranged around the lumen of the catheter to form aplurality of evenly-spaced tightly wound sections and a plurality ofevenly-spaced loosely wound sections, wherein each tightly wound sectionis spaced from a nearest tightly wound section by a loosely woundsection, wherein each tightly wound section comprises a first pitch andeach loosely wound section comprises a second pitch different from thefirst pitch.
 2. The intravascular device of claim 1, wherein eachtightly wound section comprises a first length and wherein each looselywound section comprises a second length, wherein the second length islonger than the first length.
 3. The intravascular device of claim 1,wherein the radiopaque wire is embedded within a wall of the catheter.4. The intravascular device of claim 1, wherein the catheter comprises atubular member, and wherein the radiopaque wire is positioned around anouter surface of the tubular member.
 5. The intravascular device ofclaim 1, wherein the first pitch is a closed pitch, and wherein thesecond pitch is an open pitch.
 6. The intravascular device of claim 1,wherein the radiopaque wire is disposed at a distal portion of thecatheter.
 7. The intravascular device of claim 1, further comprising anultrasound transducer disposed at a distal portion of the catheter. 8.The intravascular device of claim 7, wherein the ultrasound transducercomprises an intravascular ultrasound (IVUS) imaging transducer.
 9. Theintravascular device of claim 1, wherein the catheter further comprisesa therapeutic device disposed at a distal portion of the catheter. 10.The intravascular device of claim 10, wherein the therapeutic devicecomprises at least one of a balloon or a stent.
 11. The intravasculardevice of claim 1, wherein the radiopaque wire comprises a metallicwire.
 12. The intravascular device of claim 1, wherein the radiopaquewire comprises a radiopaque polymer.